How do persuasive health messages work? A health education field study.

The authors tested an empirical definition of comprehension and investigated the relationship between comprehension, retention, attitudes, beliefs, and behavioral change in response to a persuasive health message. The study used a randomized post-tests only design with one experimental and one control group. A booklet about exercise was given to experimental group participants in their homes. They were interviewed immediately after reading the booklet and one month later. Control group participants were interviewed at both times without exposure to the booklet. The authors found that participants who were able to operationalize key concepts related to the exercise message were the most likely group to have performed the recommended behavior according to self-reports. Measures of recognition and recall were not significantly related to behavior, but measures of psychological-operational meaning (defined as the learner's ability to use the information and relate it to his/her own life) were related significantly to self-reported behavior. The authors also examined the relationship of comprehension to other variables, such as attitudes, beliefs, and behavior. The study's results support the hypothesis that comprehension is a necessary but not sufficient precursor of behavior. Implications for both program design and measurement are discussed.